You accidentally step into quicksand. You begin to sink. Can you drown? Quicksand is sand with so much water between its particles (颗粒) that it is soupy. Quicksand can no longer support weight. So does this mean one can drown in quicksand?
      The truth is that it is very rare to drown in quicksand. This is because of two things. The first reason is that most quicksand pools are not deep. Usually, a person will sink only a few inches before hitting solid ground. If it is a deep pool, an adult will usually hit solid ground after sinking only to his or her waist (腰部). Deeper pools are rare, but even then, there is a reason why people are not swallowed up after accidentally stepping into quicksand.
  The reason is that quicksand is dense. When something is dense, its particles are crowded close together. Quicksand is denser than the human body. This means that humans will naturally float in quicksand! The upward push of quicksand is greater than the downward push of the human body.
        Usually you will sink to your chest before you begin to float. Your lungs, acting like giant balloons, help you float. You will only sink further if you are loaded down, perhaps with a heavy pack. Take off your pack, and you cannot drown. You cannot be swallowed.
        One man escaped from quicksand after he sank up to his chest. How did he do it? He swam. People can swim in quicksand if they move slowly enough. The man slowly made swimming motions with his arms and legs. He swam slowly and carefully for one hour. He did not stop making the swimming motions once. Finally, he reached the edge of the quicksand pool. He did not drown. He climbed out unharmed.

  本时文内容由奇速英语国际教育研究院原创编写，禁止复制和任何商业用途，版权所有，侵权必究！

1.According to the text, quicksand is sand _____.

A with high temperature

B mixed with a lot of water

C that we see on the beach

D that can pull everything into it

解析：选B。细节理解题。根据第一段第四句Quicksand is sand with so much water between its particles that it is soupy. 可知，流沙是沙和水的混合物，故选B。

2.Which statement does the text lead you to believe?

A People often drown in quicksand.

B Most quicksand pools are very deep.

C Only fat people can be trapped in quicksand.

D People won’t be swallowed up even in deep quick sand pools.

解析：选D。细节理解题。根据第二段最后一句Deeper pools are rare, but even then, there is a reason why people are not swallowed up after accidentally stepping into quicksand.可知，即使流沙池较深，人们也不会在陷入流沙之后被吞没，故选D。

3.Why do people float in quicksand?

A Because quicksand pools are usually not deep.

B Because quicksand can support heavy weight.

C Because quicksand is denser than the human body.

D Because the downward push of quicksand is greater.

解析：选C。细节理解题。根据第三段第三、四句Quicksand is denser than the human body. This means that humans will naturally float in quicksand! 可知，流沙比人的密度大，这意味着人体在流沙中会自然地漂浮起来，故选C。

4.We know from the last paragraph that you can escape from quicksand by_____.

A swimming slowly

B holding your breath

C struggling very hard

D taking off your clothes

解析：选A。细节理解题。根据最后一段第二、三句How did he do it? He swam. 可知，人们可以通过缓慢地游泳从流沙中脱身，故选A。

5.The text mainly talks about _____.

A quicksand pools

B the dangers of quicksand

C the formation of quicksand

D ways to escape from quicksand

解析：选D。主旨大意题。本文前四段重点解释人被困流沙后为什么不会被吞没。最后一段通过一个例子给出了从流沙中脱身的方法。即，整篇文章都是围绕着“脱困流沙”这一话题展开的，故选D。